With the automobile becoming a dominant mode of transport in today's world, automobile users are paying greater attention to automobile safety issues as a result of the increasing propensity of accidents. For example, one of the safety features that people consider when purchasing an automobile is the airbag, which plays a key role in automobile safety performance. Because the bar for automobile safety standards is continuously set higher due to advances in technology and government regulations, in order to improve the overall safety performance of the automobile, the performance requirement of the airbag has to be raised. This has led to stricter performance requirements of the gas generator, which is a key component of the airbag.
Currently, there are three types of gas generators: a pyrotechnic type, a high pressure gas cylinder type, and a hybrid type. The pyrotechnic gas generator is widely used, but has some disadvantages. For example, its gas production is not stable, and the residues produced may pollute the environment. Although the gas generator of the high pressure gas cylinder type has no residue pollution problem, its gas production speed is difficult to control. The hybrid gas generator combines advantages of both the pyrotechnic gas generator and the high pressure gas cylinder gas generator. One example of a hybrid gas generator in the airbag that is used in an automobile for side impact protection has been disclosed in Chinese Patent serial number CN2772902, which teaches a gas generator comprising a high pressure gas cylinder and a gas producing device. The high pressure gas cylinder has one end connected with the gas producing device. The gas producing device may comprise a pyrotechnic gas cylinder with two open ends, and a powder producing chamber inside the pyrotechnic gas cylinder. The powder producing chamber has one end provided with an electric igniter, and the other end formed with a conical neck. The pyrotechnic gas cylinder has an open exhaust hole. An arch-shaped bursting disc is provided at one end of the pyrotechnic gas cylinder. The conical neck of the powder producing chamber regulates the gas releasing direction of the gas in the powder producing chamber, which aids in breaking the bursting disc. However, the deploy speed of the airbag may not be optimal, since the gas may not be able to timely escape from the exhaust hole due to the conical neck occupying much of the relatively small exhaust space.